@article{DAN_1961_139_6_a4,
     author = {S. G. Krein and Yu. I. Petunin},
     title = {A relationship criterion for two {Banach} spaces},
     journal = {Doklady Akademii Nauk},
     pages = {1295--1298},
     publisher = {mathdoc},
     volume = {139},
     number = {6},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_139_6_a4/}
}